ITK/Using ITK from .NET

This page describes how to use ITK from .NET.
NOTE: You must build ITK, wrapper DLL, and .NET exe all using the same target platform i.e. Win32/x86 or Win64/x64

1. Download CMake, ITK source code, and SWIG
2. Build ITK (see here for help)
3. Create the following CMakeLists.txt file:

   <syntaxhighlight lang="make">

   1. File: CMakeLists.txt

   cmake_minimum_required(VERSION 2.8)

   project(ExampleWrapper)

   find_package(ITK REQUIRED) include(${ITK_USE_FILE})

   add_library(ExampleWrapper SHARED example.h example.hxx example_wrap.cxx) target_link_libraries(ExampleWrapper ${ITK_LIBRARIES}) </syntaxhighlight>

4. Create the following example.h file:

   <syntaxhighlight lang="cpp"> // File : example.h

   1. ifndef __example_h
   2. define __example_h

   1. include <string>

   template<class TPixel, unsigned int VDimension> void SmoothImage(

      const std::string input, const std::string output, const double sigma
   

   );

   1. include "example.hxx"

   1. endif // __example_h

   </syntaxhighlight>

5. Create the following example.hxx file:

   <syntaxhighlight lang="cpp">

   1. ifndef __example_hxx
   2. define __example_hxx

   1. include "example.h"

   1. include "itkImage.h"
   2. include "itkImageFileReader.h"
   3. include "itkImageFileWriter.h"
   4. include "itkSmoothingRecursiveGaussianImageFilter.h"

   template<class TPixel, unsigned int VDimension> void SmoothImage(

      const std::string input, const std::string output, const double sigma
   

   ) {

      // Read input
      typedef itk::Image<TPixel,VDimension> ImageType;
      typedef itk::ImageFileReader<ImageType> ReaderType;
      ReaderType::Pointer reader = ReaderType::New();
      reader->SetFileName(input);
      reader->Update();
   

      // Apply filter
      typedef itk::SmoothingRecursiveGaussianImageFilter<ImageType> FilterType;
      FilterType::Pointer filter = FilterType::New();
      filter->SetInput(reader->GetOutput());
      filter->SetSigma(sigma);
      filter->Update();
   

      // Write output
      typedef itk::ImageFileWriter<ImageType> WriterType;
      WriterType::Pointer writer = WriterType::New();
      writer->SetInput(filter->GetOutput());
      writer->SetFileName(output);
      writer->Update();
   

   }

   1. endif // __example_hxx

   </syntaxhighlight>

6. Create the following example.i file (instructs SWIG how to generate the wrapper):

   <syntaxhighlight lang="cpp"> // File : example.i %module example %include "std_string.i"

   %{

   1. include "example.h"

   %}

   %include "example.h"

   %template(SmoothImageUC2)SmoothImage<unsigned char, 2>; %template(SmoothImageF2) SmoothImage<float, 2>; </syntaxhighlight>

7. Run SWIG using the following command: swig -c++ -csharp -dllimport ExampleWrapper example.i
   The following files should be generated:
   • example_wrap.cxx
   • example.cs
   • examplePINVOKE.cs
8. Run CMake, configure and generate, build the project. The result should be ExampleWrapper.dll
9. Create the following C# runme.cs file:

   <syntaxhighlight lang="csharp"> // File: runme.cs using System;

   public class runme {

      [STAThread()]
      static void Main() {
          try {
              example.SmoothImageUC2(
                  input: "C:/Temp/cthead1.png",
                  output: "C:/Temp/cthead1-smooth.png",
                  sigma: 5.0
              );
          } catch (Exception ex) {
              Console.WriteLine(ex);
          }
      }
   

   } </syntaxhighlight>

10. Build the .NET executable. For Mono use the following: mcs -platform:x86 -target:exe -out:example.exe runme.cs example.cs examplePINVOKE.cs
11. Run the .NET executable. Make sure it can find ExampleWrapper.dll (the easiest way is to copy the dll to the same folder as example.exe)